One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10,15,13)(11,19,20,16)(12,17,21,22)(14,18,24,23)(27,36)(29,39)(32,37)(33,38)(1,2)(3,6)(4,7)(5,8)(9,11,15,20)(10,16,13,19)(12,14,21,24)(17,23,22,18)(25,26,31,35)(27,37,36,32)(28,30,34,40)(29,33,39,38)(11,20)(14,24)(16,19)(18,23)(25,27,31,36)(26,32,35,37)(28,39,34,29)(30,33,40,38)(1,3,5,4)(2,6,8,7)(9,12,15,21)(10,17,13,22)(11,14,20,24)(16,23,19,18)(25,28,31,34)(26,30,35,40)(27,29,36,39)(32,38,37,33)(1,4,5,3)(2,7,8,6)(9,13,15,10)(11,19,20,16)(12,17,21,22)(14,23,24,18)(25,29)(26,33)(27,28)(30,37)(31,39)(32,40)(34,36)(35,38)(9,14)(10,18)(11,21)(12,20)(13,23)(15,24)(16,17)(19,22)(25,30)(26,34)(27,38)(28,35)(29,37)(31,40)(32,39)(33,36) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.